diff --git a/src/eval.c b/src/eval.c
index 4ba4121..c63a5e0 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -21802,7 +21802,7 @@
 	fp = HI2UF(hi);
 
 	if (fp->uf_flags & FC_DICT)
-	    return NULL; /* don't show dict functions */
+	    return ""; /* don't show dict functions */
 
 	if (STRLEN(fp->uf_name) + 4 >= IOSIZE)
 	    return fp->uf_name;	/* prevents overflow */